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💡 #Highcitedpaper KRISO(Korea Research Institute of Ships & Ocean Engineering) 🌊 Title: Dynamical Sliding Mode Control for Robust Dynamic Positioning Systems of FPSO Vessels 🔑 Keywords: #dynamicpositioning systems; #marinevessel; #slidingmodecontrol; extended #Kalmanfilter; #Lyapunov stability; time-domain simulation 🔗 Check here: https://lnkd.in/daXc2CkD 📜 Abstract：The conventional proportional derivative (PD) control algorithm with appropriate gain scheduling is generally applied to a dynamic positioning (DP) system. However, finding appropriate gains through gain scheduling makes the DP system more complicated. A sliding-mode control algorithm controls an arbitrary point, such as the turret system on a floating production storage and offloading (FPSO) vessel. This algorithm was developed for DP and can be applied to FPSO vessels considering the uncertainty of the vessel dynamics, unknown time-varying environmental disturbances, and transient performance. To control an arbitrary point on the FPSO vessel using a DP controller, the Jacobian matrix in the kinematic equation is modified to present the arbitrary point in the control. The Lyapunov stability theory is applied in the design of the SM control algorithm to provide robustness to the control system. A time-domain simulation tool was developed to verify the effectiveness of the proposed SM control algorithm. The performance of the control algorithm was evaluated numerically to address its efficacy. The results were compared with those obtained using the conventional PD control algorithm.

At IMDC, we are committed to driving innovation in complex marine infrastructure projects, including immersed tunnels. The transportation and installation of submerged tunnel elements are critical phases that require precision and safety. By leveraging advanced numerical simulations, IMDC supports contractors in ensuring that each operation is conducted smoothly, efficiently, and with the highest safety standards in place 👷 By utilizing state-of-the-art numerical models, we provide comprehensive support in optimizing the transportation and installation processes. Our tools help simulate and analyze key factors such as hydrodynamics, seabed conditions, and forces acting on the structure during towing, immersion, and final positioning. Benefits of IMDC’s Numerical Tools include: 🔶 Accurate simulations of hydrodynamic forces to reduce risks 🔶Optimization of installation procedures to save time and costs 🔶Real-time data analysis for decision-making support during critical phases 🔶Load Simulations from Passing Vessels to ensure structural stability prior to backfilling. 🔶Insights in mud behaviour when installing in sedimentation-prone environments Together, let's elevate the standards of submerged tunnel installation! If you want to know more contact our colleagues Foteini Kyrousi and Boudewijn Decrop or visit our website www.imdc.be. #ExpertsinWater #Trust #PoweredbyIMDC #MarineEngineering #TunnelConstruction #NumericalTools #Hydrodynamics #Innovation

Great week for Bureau Veritas | Marine & Offshore team’s at OMAE Conference in Singapore, 6 technical papers have been presented: - OMAE2024-123789 Elastic-Plastic Buckling Analysis of a Ship Circular Hollow Pillar Under Compression and Bending Loads: Analytical Resolution and Comparison to Finite Element Analysis. @Aurelien Nicolas - OMAE2014-121843 Static and Fatigue Strength Assessment of Composite Patch Repairs. stephane paboeuf - OMAE2024-123176 Engineering Critical Assessment for Alternative Materials to IGC Code for Lco2 Carriers Type-C Tanks. @Fabien Conti - OMAE2024-127678 Fluid Structure Interactions for Ship Advancing in Waves With Constant Forward Speed. Quan Nguyen Minh - OMAE2024-126667 Time-Harmonic Ship Waves From the Perspective of an Earth-Fixed Observer. @xiabo Chen - OMAE2024-130908 Static and Fatigue Analysis of Wind Turbine Towers Made in Composite Materials. stephane paboeuf #structural, #integrity, #composite, #hydrodynamics, #sustainibility

Successfully completed NPTEL online course on "Geotechnical Engineering Laboratory".

Offshore Rig Storm Simulation Ensuring the stability of oil rigs during storms with significant wave activity requires meticulous engineering and robust foundation design. Key systems include jacket structures, tension leg platforms (TLP), gravity-based structures (GBS), and floating offshore structures. These foundations must distribute loads evenly and anchor securely to the seabed using high-strength materials and advanced anchoring techniques like suction caissons or driven piles. Additionally, dynamic positioning systems and ballast control can be integrated to enhance stability during severe weather conditions.   CFD is crucial for optimizing the design of offshore installations such as oil rigs and offshore wind turbines, and predicting their behavior under extreme ocean weather conditions. CFD simulations model the complex interactions between multiphase fluids and fluid-structures, enabling us to better understand the stress impact of waves and wind on the structure, and the vibrations induced by the vortex dynamics of flows. By analysing these factors, foundation designs can be refined, mooring configurations optimized, and structural resilience enhanced. This ensures potential issues are addressed in the design phase, leading to safer and more cost-effective offshore installations.   At Zelin, we offer advanced engineering solutions to contribute to innovation and to optimize offshore installations design. #CFD #Engineering #FluidDynamics #Aerodynamics #Innovation #Science #Technology #Physics Sources: - https://lnkd.in/gey_BDF7 - https://lnkd.in/gduAPd4C - https://lnkd.in/gCjUhZwW

Valve malfunctions and valve leaks are the largest contributors to hydrogen incidents at NASA, accounting for 20% of the incidents. Leaking connections are the second largest, accounting for 16% of the incidents. Inspection activities for hydrogen systems include 🔹leak testing 🔹checking for continuous flow from vent systems 🔹operational checks for valves, especially relief and check valves 🔹functional checks and calibration of instruments Connections should be regularly inspected for any sign of corrosion, erosion, cracking, bulging, blistering, or other deterioration. #hydrogen #inspection

⚡Offshore Rig Storm #CFD Simulation⚡ Ensuring the stability of oil rigs during storms with heavy waves demands precise engineering and strong foundation design. Key systems include jacket structures, tension leg platforms (TLP), gravity-based structures (GBS), and floating offshore structures. These foundations must evenly distribute loads and securely anchor to the seabed using high-strength materials and advanced anchoring techniques like suction caissons or driven piles. Dynamic positioning systems and ballast control further enhance stability during severe weather. CFD is vital for optimizing offshore installations like oil rigs and wind turbines. These simulations model interactions between fluids and structures, helping predict stress from waves and wind and vibrations from vortex dynamics. By analyzing these factors, designs can be refined, mooring optimized, and structural resilience improved, ensuring safer and more cost-effective offshore installations. 🌎 Sources: https://lnkd.in/e_ujt-E // https://lnkd.in/ezZ_Zmkt // https://lnkd.in/eBD3P3-S #engineeredmind #science #technology #engineering #cfd #simulation

25 Years of Operational Modal Analysis 😃💪 It is with great pride that we celebrate our 25th anniversary this year. On March 1st, 1999, Structural Vibration Solutions A/S was founded as a spin-off from Aalborg University in Denmark. Our first software release, ARTeMIS Extractor, was made in 2000 and included the two patented Frequency Domain Decomposition methods FDD and EFDD as well as three versions of the Stochastic Subspace Identification (SSI) methods. ARTeMIS Extractor has been succeeded by the more powerful ARTeMIS Modal that has a new look and feel. However, the philosophy is the same as it was back when we started. The user should have different methods available for analysis of the measurements to enable a validation of the modal results. Today, our software is used by mechanical engineers for modal analysis of operating machinery and components, and by civil engineers for ambient vibration analysis of large structures like bridges and buildings. New Software Release Coming Soon 🤩🎉 We are very proud of the impact our solutions offer our customers and we will use our anniversary year to launch some interesting new software solutions in the upcoming ARTeMIS Modal 8.0.  We look forward to announcing the new product release very soon💡 Follow us for more news 😃   #structuralvibrationsolutions #operationalmodalanalysis #software #experimentalmodalanalysis 

Tensioned flexible riser vibrations under wave excitation, an investigation on the scale effect - Frontiers in Marine Science: In order to study the scale effect in wave-structure interactions and the role that structure-related parameters (tension T or bending stiffness EI) plays, riser model tests under regular waves were conducted using the model with multiple geometric scales (1:15, 1:12 and 1:9) in a wave basin. The riser model used is a novel structural design combing the outer polyvinyl chloride pipe with the core steel rod which could be simplified as a cantilever beam. Different initial tension T acting on the riser are tested by adjusting the slotted weight. The results show that the amplitude varies in a cubic fashion with the distance from the fixed end. In addition, the influence of the wave period and top tension T on the amplitude are investigated, which ultimately leads to a dimensionless number π1 = KCd·TL2/EI where KC is the classical Keulegan–Carpenter number (KC), EI shows the bending stiffness of the riser model and L gives the pipe length. With the KC number revised to take the distance from the fixed end into the calculation, this parameter provides a good measure in estimating the amplitudes of the riser vibrations induced by the waves.

⚙️ NTSB Engineer Highlights Structural Flaws in Titan Submersible’s Carbon Fiber Hull ⚙️ New findings from the NTSB have revealed that the Titan submersible’s carbon fiber hull exhibited structural flaws, contributing to concerns around its integrity. This report underscores the critical role material science and engineering play in ensuring safety in extreme environments like deep-sea exploration. As engineers, this incident reinforces the importance of combining innovation with stringent safety standards to protect lives and push technological boundaries responsibly. Learn more: https://ow.ly/vPKC50TEliC #EngineersClubStLouis #EngineeringInnovation #MaterialScience #SafetyStandards #DeepSeaExploration #SubmersibleEngineering